Hoisting apparatus



April 21, 1925.

'A. E. NORRIS HOIS'IING APPARATUS 3 Sheets-Sheet 1 Filed May 6, 1924 Invenior: :HZmonEZtZa/rnis. 3

April 21, 1925. 1,534,538

A. E. N ORRIS HOI STING APPARATUS Filed may 6, 1924 s Sheets- Sheet s Patented Apr. 21, 1925.

UNITED STATES ALMON E. nonms, or BRO OKLINE, MASSACHUSETTS.

HOISTING APPARATUS.

Application filed May 6, 1924 Serial in; 711,379.

To all whom it may concern:

- Be it known that I, ALMON E. NORRIS, a

.citizen of the United States, and a resident of Brookline, in the county of Norfolk and State of Massachusetts, have invented an Improvement in Hoistin Apparatus, of which the following descrlption, in connection with' the accompanying drawings, is a specification, like characters on the drawings representing like parts.

This invention relates to hoisting devices and consists in improvements relating to .the

control and operation of such devices.

The invention will be best understood by reference to thefollowing description when taken in connection with the accompanying illustration of one specific embodiment thereof, while its scope will be more particularly pointed out in the appended claims.

In the drawings I Fig. 1 shows more or less diagrammatically one form of the invention embodied in a simpletype of electrically driven hoist,

I the latter comprising a rope or cable winding drum;

Fig. .2 is a side elevation of the brake drum and brake for the winding drum shown in Fig. 1;

Fig. 3 is a side elevation showing the controller and the lost motion. connection between the same and the brake operatingswitch for automatically releasing and applying the brake and illustrating the parts in the closed position of the switch corresponding to the released position of the brake;

Fig. 4 is an end view in partial section showing the parts illustrated in Fig. 3;

Fig. 5 is a detail in side elevation showing the parts in the open position of the switch;

Fig.'6.is an end elevation, partly broken away, showing the brake drum;

Fig. 7 is a sectional elevatlon of the drum; and 5 1 Figs 8 is adetail in sectionshowing-the arrangement of vanes on the interior of the drum, the section being taken on the line 88 in Fig. 6. p

- Referring to the drawings and to the illustrative embodiment ofthe invention, the same is shown as comprising a load hoisting or lowering device, herein. in the form of a windingdrum 11, adapted, to raise or lower a load through the rope or cable -13, the drum being connected through gears 15- and 17 to be driven by the. electric motor 19.

The hoisting drum is provided with a brake 21 cooperating with a brake drum 23 and adapted to hold the load as required, the brake herein being of a general construction similar to that disclosed in Letters Patent No. 1,123,786, granted to me January 5, 1915. In such aconstruction thebrake automatically prevents the unwinding movement of the drum under the pull of the load, except when released by the operator. As herein shown, the brake band 21 is connected to a brake lever 25 and a link 27 of the general construction disclosed in the aforesaid patent, so that, when the drum tends to unwind the cable by turning in a clockwise direction (Fig. 2), the link, which is normally positioned by a spring 29, is drawn up by reason of the friction of the band. This enforced movement of the link automatically closes and applies the brake, The rotation of the drum in the opposite direction draws the link toward a center line passing from the axis of the hub to the point of pivotal support of the link, thereby automatically opening or unclas ing the band and leaving the drum free or winding on the cable. l

The brake may be positively released for unwinding movement of the drum or rotation in a clockwise direction (Fig. 2) by releasing movement of the lever 25. To accomplish this, the lever is connected to be lifted by a" link 31 with one arm of a bellcrank lever 33, the remaining arm of which is pivotally connected to the stem 35 of a piston 37 in the cylinder 39, the latter hav- 1ng a supply pipe 41 leading thereto for conducting pressure fluid to the cylinder from'a pressure fluid supply. The opposite end of the stem 35 is connected to a plunger 43 against which works a spring 45. The admission of pressure fluid to the cylinder is under the control of the operator, as will more fully appear, the brake being normally.

from the cy1in-- i control is exercised over the motor and the brake. The controller which is connected to the motor by conductors 53 and the controller lever may be of the general construction and arrangement shown in my prior Patent No. 1,419,167, granted June 13, 1922, in which there is disclosed a systemof con-v trol for an alternating current hoist motor, the latter having such connection through the controller that in the lowering position of the latter the descent of the load is checked through the assistance of regenerative braking.

Referring to Figs. 3 and 4, the controller lever 51 is secured to the hub 55 of the gear sector 57 which latter meshes with a pinion 59 mounted on the controller shaft 61, the arrangement being such that when the lever is thrown to the right of the neutral position (shown in dotted lines in Fig. 3) the motor is connected to be driven in a direction to hoist the load. When the cont-roller lever is moved to the full line position, or to the left of the neutral position (as viewed in Fig. 3), the motor is reversely connected for lowering the load under regenerative brakmg.

Secured to the hub 55 of the sector gear 57 to turn therewith is a brake actuating cam 63, the face of which is adapted to engage with a cam roll 65, and the movement imparted to the latter acts to control. the brake automatically and coordinately with the movement of the motor controller. The general arrangement, as will more fully appear, is such that, in the hoisting position of the controller lever, fluid pressure is withdrawn from the brake cylinder 39 and the brake lever so held by the spring 45 as to prevent reverse or unwinding movement of the drum. The same condition pertains when the controller lever isin the neutralposition. When the controller lever is moved to or toward the full line position shown in Fig. .3, however, to lower the load, the shape-of the cam is such that pressure fluid is admitted to the brake cylinder and acts automatically to release the brake.

Where regenerative braking is availed of with an alternating current motor, the usual arrangement is to provide forthe reversal of the supply currentto the motor in the lowering position of the controller, the rotor being initially connected through a resistance which is reduced as the controlleris moved through successive steps until, in the full lowering position of the controller, all or substantially all resistance is out of the rotor circuit. The load, meantime, has accelerated until the rotor runs slightl above synchronous speed, at which point -1t tends to be held by the regenerative effect.

Under these conditions of operation, it is desirable to promptly release the brake on initial movement of the controller -from its regenerative braking eficctive, so that the load may be promptly brought to rest or suitably controlled as soon as the braking effect of the rotor is withdrawn.

Although the brake might be controlled by a valve or other control element located at the control stand, in the illustrated embodiment of the invention the valve is located adjacent the hoisting apparatus and is itself controlledelectrically by means of a switch located at the control stand. This reduces to a minimum the piping connections to the brake cylinder and the amount of pressure fluid required to be maintained therein and makes it practicable to locate the controlling stand at a cpnsiderable distance from the hoisting apparatus.

To provide a control for the brake which will cause its release on the initial movement of the controller from neutral position toward lowering position and its application on initial movement in'a reverse direction, I have provided between the cam 63 and the valve controlling switch a lost motion or slip connection'which causes the switch to close and the brake to release when the controller is first moved to lower the load, but also causes the switch to 'open and the brake to apply as soon as the controller is moved reversely from either its full lowering position or from any intermediate position.

Referring more particularly to Figs. 3, 4 and 5,,there is provided a switch block 67 of insulating material carrying the contact 69 adapted to bridge theseparate contacts 71 which-are contained in a valve controlling circuit, to be later described. The switch block 67 is connected to the guide yoke 73, the latter having a grasping portion 7 5 which comprises two split or separated parts, one attached to each branch of the yoke and normally forced toward each other byvsprings 77. The latter are mounted'one on each of the two studs I9 and are held between a washer on the stud and the guide yoke itself, there being provided a stud at each side of the grasping portion, threaded into one part thereof and so arranged that the companion' part is forced against the guide rod, and the two parts, which fit about the guide rod, exert a. frictional gr1p thereon. When the guide rod is depressed, due to the frictional grip of the'yoke on the guide rod, the latter carries with it both the guide yoke and the switch block. As soon as the switch block contact 69 engages the contact 71 further depression of the guide rod causes the latter to slip through the guide yoke. On the reverse or lifting movement of the guide rod, the switch block is lifted with the initial movement of the guide rod, instantly opening tl e brake-valve controlling circuit.

The guide rod 81, which is herein rectangular in cross section, is guided for vertical movement between an upper pair 83 and a lower pair 85 of guide rollers. The latter are mounted upon studs 87' and 89. respectively, securedto the control stand, the two members of each pair of studs being connected on opposite sides of the guide rod by the cross plates 91 and 93 respectively. The guide rod 81 is normally pressed up to keep the guide roller 85 seated against the cam 63 by means of the spring 95 located in a core or pocket of the guide rod,'the lower end of the spring being seated against a spring supporting block 97 located in a transverse slot in the guide rod and having shouldered ends which rest upon the lower cross plates 93. 1 s p The brake cam 63 has an arc-shaped face portion which is presented to the cam roller 65 when the controller lever is either in its neutral position (shown in dotted lines in Fig. 3), or in a hoisting position, or. in any one of the intermediate steps of its hoisting position (to the right, of the dotted line position as shown in Fig. 3). i In these positions of the controller lever, the cam roller and the guide rod remain stationary in their uppermost positions, as represented in Fig. 5, where the lifting spring 95 is'holding the guide rod roller up against the face of the cam, the switch block having been lifted and the circuit opened, and the guide yoke clamp 75 abutting against the under side of the cross plates 95 whichhave brought the .same

to rest in the lifting movement of the guide rod.

When the controller handle 18 moved from neutral toward a lowering position, or counterclockwise as viewed in-Fig. 3, the cam roller is engaged by a cam face of increasing radius, causing the depression of the guide rod and the almost instant closing of the circuit through the depression of the switch 67, which follows the movement of the guide rod owing to the frictional grip of the guide-yoke thereon. The range of movement of the yoke and switch :lS relatively slight, so that the switch is closed on the initial movement of the controller lever and before the controller is moved to its first lowering step. As the controller is moved further away from its neutral posi tion, the cam roller 65 meets the cam face of gradually increasing radius so that the guide rod continues to move downward, the grasping member on the guide rod yielding or slipping to permit this relative movement. The downward movement of the guide rod continues until the full lowering position of the controller lever has been reached or that in which substantially all resistance has been cut out of the rotor circuit, such position being represented in full lines in Fig. 3. If the controller lever is moved from the full lowering position toward neutral position, on the first movement thereof the guide rod rises under the depres- ,tial movement of the lever toward the full lowering'position, whether such movement be started from neutral or from any inter' mediate position. That is to say, in any position on the lowering side of the controller, a very slight movement ofthe lever clockwise (as viewed in Fig. 3) will apply the brake and a very slight movement counterclockwise will release the brake.

Referring now to the brake .controllin'g device intermediate the switch 67 and the brake cylinder 39, the latter is connected through the supply pi e 41 with the cylin der port 99of the va ve casing 101. The valve may be of the general type shown in my prior Patents No. 1,088,293, dated Feb. 2 1, 1914, and No. 1,238,184, datedAug. 28, 1917. Within the valve casing there is provided a piston valve 105 comprising two spools of equal diameter, with an intermedi ate portion of reduced diameter. The valve 105 abuts at one end against the spring 107 and at the opposite end against the end of the actuating rod 109, the latter passing through a stufling box in the end of the valve casing. Compressed air or other suitable pressure fluid is supplied to the valve through the supply pipe 111 and supply port 113. The valve casing is connected through the eithaust pipe 115 which latter opens to the exhaust port 117.

The cylinder port 99 is connected-by 8. b1 pass or run-a-round port 119 with a space 121 to which the end of the valve is exposed, so that the latter, when the pressure is admitted to the brake cylinder, is subjected to an end pressure proportional to that in the brake cylinder, tending to move the valve against the actuating rod 109.

The contacts 71 at the controller stand, controlled by the switch block 67, are arranged within a circuit 123 which includes -the battery 125, or. other suitable source of IOU that the solenoid actuated movement of the connection 137 compresses the spring and exerts a yielding pressure through the valve rod against the valve, causing the latter to rise and connect the ports 113 and 99, admit ting pressure fluid to the brake ciylind er and serving to release the brake. The spring 141may be so adjusted that when the pressure in the brake cylinder has risen to a predetermined point, the action of the fluid pressure on the end of the valve through the run-a-round port 119 will suflice to move the valve back to its neutral position shown in Fig. 1, the spring 141 compressing under such movement. Shouldthe pressure in the brake. cylinder drop for any reason, as through leakage, the pressure of the spring 141 will then suffice to again raise the valve and admit pressure fluid until the balance has been restored.

As soon as the circuit is broken through the lifting of the switch block at the control stand, the compression on the spring 141 is relieved, the solenoid parts are moved to their open position, and the valve will be thrown to connect the cylinder port 99 with the exhaust port 117, this serving to exhaust pressure from the brakecylinder and cause the spring 45 to apply the brake.

The flow of pressure fluid to the valve and the brake cylinder and the exhaust from the brake cylinder may be more or less retarded and the brake thereby gradually released or applied, following the sudden and complete movement of the valve 105. This result, for example, may be secured by providing the throttle valve 143 in the supply pipe 111 and a similar valve 145 in the exhaust pipe 115. By adjusting these throttle valves, action of the brake either in respect to application or release may be retarded as desired.

In handling loads in connection with regenerative braking, the latter is available for limiting the rate of descent of the load,

but the load must be brought to rest through the action of a mechanical brake. This subjects the latter'to severe service and this is especially the case in large units, where the momentum of the rotor of the hoisting motor may equal or exceed that of the load itself. In connection with the described hoisting apparatus, therefore, I have provided a brake drum which is so constructed as to maintain a very effective cooling current of air across the inner face of the drum, so that an effecmemes tive dissipationof the heat generated by the friction band of the brake is secured.

Referring to Figs. 6 and 7, the brake drum 23 is bolted to the end of the hoisting drum 11 by means of the disk-shaped wall 147, which latter is somewhat dish shaped in order to'suitably locate the brake drum on the hoisting drum. The wall 147, however, forms a separating or partition wall between opposite sides of the brake drum interior but is terminated short of the brake drum rim. This would leave an annular space between the edge of the wall 147 and the inner circumferential wall of the brake drum were it not for the provision of a succession of vanes or blades 149 which are arranged at an inclination to the direction of rotation and serve as the mechanical connection of the wall 147 to the rim 23 and atthe same time separate the annular space referred to into a seriesof separate passages 151. In the operation of the hoisting apparatus, when the drum is reversely rotated for lowering the load, the vanes 149 move in such direction as to force the air across the inner face of the rim. As the drum rotates the cool air is drawn from the inner part of the drum radially dutward over the inner partition wall 147 due both to centrifugal action and to the lateral displacement of the air at the rim through the passages 151. As it reaches the outer edge of the partition wall it is engaged by the inclined vanes and forced to the opposite sides thereof and across the inner wall of the rim, producing a steady passage of cooling air acrossthe inner wall of the rim and assisting in conducting away the heat generated by the friction of the brake band.

The operation of the controlling mechanism for the hoisting apparatus will be readily understood. When it is desired to hoist the load, the controller lever is moved from the neutral, or dotted line position shown in Fig. 3, in a clockwise direction, this serving to.v rotate the motor positively for raising the load and maintaining the brake controlling switch open and the brake applied, or, in other words, permitting the winding-0n rotation of the drum but in a position to prevent reverse or unwinding rotation thereof. Whenever the controlling lever is thrown back to neutral position, the motor is stopped and the brake still remains effective for holding the load. I

When it is desired to lower the load th controller is moved counterclockwise from the dotted line position shown in Fi 3 to its first loweringstep or; position. 11 this position the motor current is reversed butthe rotor connected through more or less resistance, permitting the motor and the load to quickly accelerate without excessive.

' is depressed against th guide rod 81 and this serves to close the switch and release the brake, so that the motor starts its reverse movement without the retarding action of the brake. As the acceleration increases, the handle is, moved step by step 'to the full lowering position (represented by full lines in .Fig. 3), cutting out successive resistances until, in the full lowering position, the rotor is short circuited and the regenerative braking becomes effective to hold the speed approximately to synchronous speed. During this movement of the controller the guide rod continues to move down but slips through the grasping member 75 and has no effect on the switch. In case of excessive speed due to any cause, a centrifugal governing device may be utilized, such as described in my aforesaid prior Patent No. 1,419,167.

If the controller lever is moved reversely or in a clockwise direction (as viewed in Fig. 3), eitherfrom the full lowering position sothat the rotor is deprived of the effect of regenerativebraking, or from any position intermediate the full lowering position and neutral, its initial movement is a ccompanied by arise of the guide arm 81 and the practically instant opening of the switch 67 and application of the brake.

As the switch opens the guide yoke contacts with the cross bars 93 and stops further movement of the same, subsequent movement of the controller causing the guide rod to slip through the grasping member 7 5. This permits the operator to have complete control of the load at all times, while preventing any opportunity for the application of the brake while the motor is reversed during the lowering of the load.

While I have herein shown and described for the purposes of illustration one specific embodiment of the invention and in simplified form, it is to be understood that the same may be applied to widely difierent uses and embodied in widely diiferent forms and relative arrangement of parts, all without departing from the spirit of the invention.

Claims.

1. In a hoisting apparatus, the combination with a winding drum, of a braketherefor, a spring for applying the brake, a pressure fluid device for releasing the same, an electrically controlled valve for admitting pressure fluid to or exhausting the same from said device, an alternating current motor for the winding drum, a controller therefor having connections to establish regenerative brakingin lowering the load, a controller lever, and brake controlling devices operated by the lever coordinately with the controller, the same comprising a cam, a cam moved part actuated by the cam when the lever is moved between neutral and a lowering position, a switch for controlling said valve, and a lost motion connection-be tween the cam moved part and the switch providing for the simultaneous movement of the switch with the initial movement of the cam moved part when moved in either direction. whereby the movement of the lover to lower the load is accompanied by the quick releaseof the brake and the movement of the lever in the reverse direction is accompanied'by a quick application of the brake.

2. In a hoisting apparatus, the combina tion with a winding drum, of a brake therefor, electrically controlled pressure fluid means for applying and releasing the brake, an alternating current motor forthe winding drum, a controller therefor having connections to establish regenerative braking in lowering the load, and brake controlling devices automatically actuated with the controller and comprising'a brake controlling part actuated when the controller is moved between neutral and lowering position, a switch for controlling the brake, a lost motionconnect on between the brake controlling part and the switch providing for the simultaneous movement, of the switch with the initial movement of the brake controlling device in either direction, whereby'the initial movement of the controller from neutral toward lowering position is accompanied by a release of the brake. and initial movement thereof from lowering position toward neutral is accompanied by an application of the brake.

3'. In a hoisting apparatus. the combination with a load hoisting device, of a brake therefor, an alternating current motor, a controller having a hoisting. a neutral and a lowering position and having connections to establish regenerative braking in lowering the load, a brake controlling device, and a lost motion connection between the controller and said device to cause automatic release of the brake on the initial movement of the controller from neutral toward lowering position, and to cause application of the brake on the initial movement of the controller from lowering toward neutral position.

4. In a hoisting apparatus, the combina tion with a load hoisting device, of a brake therefor, an alternating current motor, a controller having a hoisting, a neutral and a lowering position and having connectionsto establish regenerative braking in lowering the load, and devices for automatically releasing the brake on initial movement of the controller from neutral toward lowering position and for applying the brake on initial movement of the controller from lowering toward neutral position.

5. In a hoisting apparatus, the combination with a winding drum, of a brake of a brake, a motor, a controller,

therefor, an alternating current motor, a controller, a controller lever, a brake controlling device connected to the controller for operating the brake coordinately therewith, and a friction connection between said device and the controller.

6. In a hoisting apparatus, the combination with a winding drum, of a brake therefor, an alternating current motor, a controller, a controller moved part, a brake controlling device, and a friction connection between the brake controlling device and controller moved part to cause the device to move initially in either direction with said part but to permit relativemovement between the same. v

7. The combination with a hoisting apparatus, of a motor, a motor controller, a controller lever, a cam moved thereby, a cam moved part, a hoist control element, and a friction connection between said part and said element permitting a relative movement between the same but causing the latter to move initially with the former in eitherdirection. I a

8. The combination with a hoisting drum, of a brake, a motor, a controller, a part moved simultaneously with the controller, a brake controlling element, and a slip connection between said part and said element permitting relative movement between the same but causing the latter to move initially with the former. Y

9: The combination with a hoisting drum,

a cones-ates trolling drum having hoisting, neutraland lowering positions, a brake controlling element, and a slip connection between the.

controller and the brake controlling element.

10. The combination with a hoisting drum, of a brake, a. motor, a controller having hoisting, neutral and lowering positions, a brake controlling element, and devices permitting the controller to move at times without movement of said element but causing actuation of the latter on initial movement of the controller toward or from its lowering position. i

11. In a hoisting apparatus, a friction drum having an outer friction surface, a series of vanes arranged transversely and obliquely across the interior of said drum, and a deflecting partition wall lying transverse the axis of the. drum and adjoining the vanes but terminating short of the interior of the drum to leave transverse passages between the vanes, into which the wall.

serves to deflect the air the device. I

Y 12, In a hoisting apparatus, a friction during rotation of drum having an outer friction. surface and an inner circumferential wall provided with a series of obliquely arranged vanes providing' air. passages between them, and a partition wallarranged transverse the axis of the drum but terminatin short of the inner circumferential wall 0 the drum.

In testimony whereof, I have signed my name to this specification.

ALMON E. NORRIS. 

